CN113691040B

CN113691040B - Motor rotor and manufacturing method

Info

Publication number: CN113691040B
Application number: CN202110762140.2A
Authority: CN
Inventors: 尚前博; 侯晓军; 庞聪; 武媛; 耿涛; 齐影
Original assignee: CRRC Yongji Electric Co Ltd
Current assignee: CRRC Yongji Electric Co Ltd
Priority date: 2021-07-06
Filing date: 2021-07-06
Publication date: 2023-07-25
Anticipated expiration: 2041-07-06
Also published as: CN113691040A

Abstract

The invention relates to the field of electric appliances, and provides a motor rotor, at least part of which is manufactured by additive, comprising: squirrel cage subassembly and motor pivot, wherein, motor pivot includes: the mouse cage comprises a mounting part, a mouse cage assembly and a connecting part, wherein the mounting part extends along a first direction, a cavity is formed in the mounting part, and the mouse cage assembly is sleeved on at least part of the mounting part; a transmission part arranged at the end part of the mounting part and extending along the first direction; in the section perpendicular to the first direction, the outer edge dimension of the mounting part is larger than the outer edge dimension of the transmission part, and the ratio of the outer edge dimension of the mounting part to the outer edge dimension of the transmission part is larger than a preset value. Such a motor rotor has a relatively light weight.

Description

Motor rotor and manufacturing method

Technical Field

The invention relates to the field of electric appliances, in particular to a motor rotor and a manufacturing method thereof.

Background

The motor rotor is a rotating part in the motor, and the squirrel-cage motor rotor generally comprises a motor rotating shaft and a squirrel-cage assembly, wherein the squirrel-cage assembly is sleeved outside the motor rotating shaft. The weight of the motor shaft is large, resulting in a large overall weight of the motor rotor.

Disclosure of Invention

In view of the above, the present invention provides a motor rotor for solving the technical problem of how to reduce the weight of the motor rotor, thereby reducing the overall weight of the motor.

According to the motor rotor provided by the embodiment of the invention, at least part of the motor rotor is manufactured by additive, and the motor rotor comprises:

a squirrel cage assembly and a motor rotating shaft; wherein, the motor shaft includes: the mouse cage comprises a mounting part, a mouse cage assembly and a connecting part, wherein the mounting part extends along a first direction, a cavity is formed in the mounting part, and the mouse cage assembly is sleeved on at least part of the mounting part; a transmission part arranged at the end part of the mounting part and extending along the first direction; in the section perpendicular to the first direction, the outer edge dimension of the mounting part is larger than the outer edge dimension of the transmission part, and the ratio of the outer edge dimension of the mounting part to the outer edge dimension of the transmission part is larger than a preset value.

Further, the cavity is arranged in the transmission part.

Further, at least one of the cavity in the mounting portion and the cavity in the transmission portion comprises a closed cavity.

Further, the mounting portion includes: the mouse cage assembly is sleeved on the sleeved part, and the transmission part is arranged at the end part of the sleeved part; the positioning part extends out of the circumferential outer surface of the sleeving part along the second direction and is abutted with one end of the squirrel cage assembly; wherein the second direction is substantially perpendicular to the first direction.

Further, the distance that the positioning portion extends from the circumferential outer surface of the sleeving portion is larger than a preset threshold value.

Further, a heat dissipation air duct is formed in the outer surface of the sleeving part, and the length direction of the heat dissipation air duct is basically parallel to the first direction.

Further, the squirrel cage assembly comprises: the rotor core extends along a first direction and is sleeved on at least part of the mounting part; the guide bars are arranged at intervals along the circumferential direction of the rotor core and penetrate through the rotor core; the end rings are respectively arranged at two sides of the rotor core and fixedly connected with the guide bars.

Further, the end faces of the guide bars extending out of the rotor core are fixedly connected with the end rings, and the distance between the end rings and the end faces of the rotor core is smaller than a preset value.

Further, the preset value is 5 mm.

Further, both end rings have mounting slots for receiving portions of the bars that are connected to the end rings.

The embodiment of the invention also provides a manufacturing method of the motor rotor, which is characterized in that the motor rotor comprises the following steps: an end ring, a motor rotating shaft; the manufacturing method comprises the following steps: and obtaining the end ring and the motor rotating shaft through additive manufacturing.

An embodiment of the present invention provides a motor rotor including: the squirrel cage assembly and motor rotating shaft, motor rotating shaft includes drive portion and the installation department that extends along first direction, and is provided with the cavity in the installation department, and the installation department of at least part is located to the rotor heart cover, wherein, in the cross-section of perpendicular to first direction, the outer fringe size of installation department is greater than the outer fringe size of drive portion, and the outer fringe size of installation department is greater than preset value with the outer fringe size of drive portion, namely, the outer fringe size of installation department is greater than the outer fringe size of drive portion far away. Through setting the outer fringe size of installation department to great size to the installation department is located to the rotor core cover, simultaneously, sets up the cavity in the inside of installation department, can understand as the inside structure integration in motor shaft's of a part of rotor core installation department, and replaces the inside solid structure of rotor core with the structure that has the cavity, thereby has reduced motor rotor's weight, and then has reduced the whole weight of the motor that has adopted this motor rotor.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a motor rotor according to an embodiment of the present invention;

fig. 2 is a cross-sectional view of a motor shaft in a motor rotor according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a motor shaft in a motor rotor according to an embodiment of the present invention;

FIG. 4 is an exploded view of a first view of a squirrel cage assembly in a motor rotor according to embodiments of the present invention;

FIG. 5 is an exploded view of a second view of a squirrel cage assembly in a motor rotor according to embodiments of the present invention;

FIG. 6 is a schematic diagram of an assembly of a guide bar and end ring in a squirrel cage assembly according to an embodiment of the present invention;

FIG. 7 is a schematic view of an assembly of another conductor and end ring in a squirrel cage assembly provided by embodiments of the present invention;

FIG. 8 is an exploded view of a bar and rotor core of a squirrel cage assembly according to an embodiment of the present invention;

fig. 9 is a schematic flow chart of a method for manufacturing a motor rotor according to an embodiment of the invention;

fig. 10 is a schematic flow chart of a method for manufacturing a squirrel cage assembly in a motor rotor according to an embodiment of the present invention;

FIG. 11 is a flow chart of a method of manufacturing a squirrel cage assembly in a motor rotor according to an embodiment of the present invention;

FIG. 12 is a flow chart of a method of manufacturing a squirrel cage assembly in a motor rotor according to an embodiment of the present invention;

fig. 13 is a flow chart illustrating a method for manufacturing a motor shaft in a motor rotor according to an embodiment of the invention.

Reference numerals illustrate:

1. a squirrel cage assembly; 10. a rotor core; 2. a motor shaft; 21. a mounting part; 211. a sleeving part; 212. a positioning part; 213. a heat dissipation air duct; 22. a transmission part; 23. a cavity; 24. reinforcing ribs; 25. a bearing sealing part; 11. a first end face; 12. a second end face; 13. a positioning groove; 20. a conducting bar; 201. a first limit structure; 30. an end ring; 301. a first end ring; 302. a second end ring; 31. a mounting groove; 311. a support groove; 312. and a limiting part.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

The individual features described in the specific embodiments can be combined in any suitable manner, without contradiction, for example by combination of different specific features, to form different embodiments and solutions. Various combinations of the specific features of the invention are not described in detail in order to avoid unnecessary repetition.

In particular embodiments of the invention, the motor rotor may be adapted to any type of motor, for example, the motor rotor may be adapted to a synchronous motor, an asynchronous motor, or a stepper motor. In the following, the structure of the motor rotor is exemplified by the motor rotor being suitable for a squirrel-cage asynchronous motor, and the type of the motor does not affect the structure of the motor rotor.

In some embodiments, as shown in fig. 1, a motor rotor includes: the squirrel cage assembly 1 and the motor rotating shaft 2, the motor rotating shaft 2 is connected with the squirrel cage assembly 1 to support the squirrel cage assembly 1. Specifically, the motor rotor 1 further includes a housing, the housing encloses to form a housing cavity, a part of the squirrel cage assembly 1 and the motor rotating shaft 2 is located in the housing cavity, two ends of the motor rotating shaft 2 are rotatably connected with the housing, the squirrel cage assembly 1 is sleeved outside the motor rotating shaft 2, meanwhile, the motor rotating shaft 2 is further connected with a rotating part of the motor rotor, and a part of the motor rotating shaft 2 extends out of the housing and is used for being connected with other devices needing to be driven so as to output kinetic energy of the motor rotor.

Wherein the motor shaft 2 includes a mounting portion 21 and a transmission portion 22. The mounting portion 21 extends in a first direction (the first direction is indicated by an arrow in fig. 1), and a cavity 23 is provided inside the mounting portion 21. The squirrel cage assembly 1 is sleeved on at least part of the installation part 21; in particular, the cage assembly 1 is provided with mounting through holes, in which at least part of the mounting portion 21 is located. The transmission part 22 is disposed at an end of the mounting part 21 and extends along a first direction, and the transmission part 22 is used for extending out of a housing of the motor rotor and connecting with other devices to be driven so as to drive the other devices.

In a cross section perpendicular to the first direction, the outer edge dimension of the mounting portion 21 is larger than the outer edge dimension of the transmission portion 22, and the ratio of the outer edge dimension of the mounting portion 21 to the outer edge dimension of the transmission portion 22 is larger than a preset value, i.e., in a cross section perpendicular to the first direction, the outer edge dimension of the mounting portion 21 is much larger than the outer edge dimension of the transmission portion 22, for example, the preset value is 2, it being understood that the outer edge dimension of the mounting portion 21 is at least 2 times the outer edge dimension of the transmission portion 22. For convenience of explanation, the design concept of the motor shaft 2 and the advantageous effects thereof will be described by taking the mounting portion 21 and the transmission portion 22 as circular axes as examples, and the outer edge dimension of the mounting portion 21 and the outer edge dimension of the transmission portion 22 will be referred to as the shaft diameter of the mounting portion 21 and the shaft diameter of the transmission portion 22, respectively, in a section perpendicular to the first direction.

The following describes the design concept of the motor shaft 2 provided in the present embodiment. The motor shaft 2 provided in this embodiment is integrally manufactured through additive manufacturing, but is not manufactured through a cutting or welding method, and for the structure of the motor shaft 2 provided in this embodiment, the shaft diameter of one part is far greater than that of the other part, if the cutting or welding method is adopted, the economy is poor, and the structure is not applicable. Specifically, the motor shaft 2 is obtained by cutting, it is necessary to manufacture a blank having a shaft diameter not smaller than that of the mounting portion 21, and cut the shaft diameter of the portion of the blank corresponding to the transmission portion 22 by cutting from not smaller than that of the mounting portion 21 to slightly larger than or equal to that of the mounting portion 21, and a large amount of metal material is consumed in the cutting process. The installation department 21 and the drive part 22 are processed respectively to install installation department 21 and drive part 22 as an organic whole through the welding, although can reduce the cutting volume of cutting, can leave the welding seam in the welding department, also have the quality risk increase problem that leads to because the deformation or the stress concentration that the welding arouses simultaneously, the wholeness of motor pivot 2 is not good, and in the rotatory in-process of motor pivot 2, the stress that motor pivot 2 received can concentrate in welding seam department, leads to motor pivot 2's life to reduce. The possibility that the problems can be reduced through additive manufacturing, specifically, the integral motor rotating shaft structure is obtained according to the actual size of each part of the motor rotating shaft 2, the cutting amount of materials can be reduced, meanwhile, the obtained motor rotating shaft 2 is high in structural integrity, the phenomenon of stress concentration can be relieved when the motor rotating shaft is stressed, and the service life of the motor rotating shaft 2 is prolonged. In summary, on the premise that the motor shaft 2 is manufactured by a cutting process or a welding process, which is not thought to be manufactured by additive manufacturing, a person skilled in the art will not design the motor shaft as the structure of the motor shaft 2 provided in the present embodiment. The specific method for obtaining the motor shaft 2 through additive manufacturing is described in other embodiments, and is not described herein.

The advantageous effects of the motor rotor to which the motor shaft 2 is applied are explained below. The diameter of the shaft of the installation part 21 is larger, and the inside of the installation part 21 is provided with a cavity, the squirrel cage assembly 1 is sleeved outside the installation part 21 with the larger diameter of the shaft, which is equivalent to replacing the solid part of the squirrel cage assembly 1 with a structure with the cavity, so that the weight of the squirrel cage assembly is reduced, the weight of a motor rotor is reduced, and the weight of the motor applying the motor rotor is further reduced. Specifically, the squirrel cage assembly 1 is provided with a mounting through hole, and at least part of the mounting portion 21 is located in the mounting through hole, so that the squirrel cage assembly 1 is sleeved on the mounting portion 21. Through setting the diameter of the shaft of the installation part 21 to be larger, the aperture of the installation through hole of the squirrel cage assembly 1 can be increased, meanwhile, the cavity 23 is arranged in the installation part 21, and the part of the solid structure inside the squirrel cage assembly 1 can be understood to be integrated in the installation part 21 of the motor rotating shaft 2, and the part of the solid structure is replaced by a structure with the cavity, so that the weight of the motor rotor is reduced, and the overall weight of the motor adopting the motor rotor is further reduced. It should be noted that only a part of the structure near the outer surface of the squirrel-cage assembly 1 participates in electromagnetic induction, and is used for enhancing the strength of electromagnetic induction, while the internal structure of the squirrel-cage assembly 1 does not participate in electromagnetic induction, the internal structure of the squirrel-cage assembly 1 is integrated in the mounting portion 21 of the motor rotating shaft 2, and the material of the part is replaced by a solid structure with a cavity structure, so that the quality of the motor rotor can be reduced on the premise that the strength of electromagnetic induction of the motor rotor is not affected.

An embodiment of the present invention provides a motor rotor including: the squirrel cage subassembly and the motor shaft who is connected with the squirrel cage subassembly, motor shaft includes drive division and the installation department that extends along first direction, and is provided with the cavity in the installation department, and the installation department of at least part is located to the rotor core cover, wherein, in the cross-section of perpendicular to first direction, the outer fringe size of installation department is greater than the outer fringe size of drive division, and the ratio between the outer fringe size of installation department and the outer fringe size of drive division is greater than the default, i.e. the outer fringe size of installation department is greater than the outer fringe size of drive division far away. Through setting the outer fringe size of installation department to great size to locate the installation department with rotor core cover, simultaneously, set up the cavity in the inside of installation department, can understand as the internal structure integration in motor shaft's of part squirrel cage subassembly installation department, and replace the solid structure of the inside of squirrel cage subassembly for the structure that has the cavity, thereby reduced motor rotor's weight, and then reduced the whole weight of the motor that has adopted this motor rotor.

In some embodiments, as shown in fig. 1, in a cross section perpendicular to the first direction, a ratio of an outer edge dimension of the mounting portion 21 to an outer edge dimension of the transmission portion 22 is greater than a preset value, and the preset value is not less than 1.5, that is, in a cross section perpendicular to the first direction, the outer edge dimension of the mounting portion 21 is at least 1.5 times as large as the outer edge dimension of the transmission portion 22, and, illustratively, in a cross section perpendicular to the first direction, the outer edge dimension of the transmission portion 22 is 100 millimeters, and then the outer edge dimension of the mounting portion 21 is not less than 150 millimeters.

In some embodiments, as shown in fig. 2, the mounting portion 21 is provided with a cavity 23 therein, and by providing the cavity 23 in the transmission portion 22, the weight of the motor shaft 2 is further reduced, thereby further reducing the weight of the motor rotor 1. Optionally, the volume of the cavity 23 provided in the transmission part 22 is smaller than the volume of the cavity 23 provided in the mounting part 21, that is, the inner space of the mounting part 21 is fully utilized, and the cavity with a larger volume is provided in the mounting part 21 with a larger volume, thereby further reducing the overall weight of the motor rotor 1. It should be noted that the cavities 23 in the mounting portion 21 and the transmission portion 22 may be provided in any form, for example, the cavities 23 in the mounting portion 21 and the transmission portion 22 may be provided at intervals along the first direction, for example, the cavities 23 in the mounting portion 21 and the transmission portion 22 may also extend along the first direction and communicate with each other. The size of the cavity in the transmission part 22 is also determined according to the strength of the transmission part 22, so that the transmission part 22 does not break or deform while transmitting the torque.

Optionally, the end of the transmission part 22 is provided with a cavity 23, and after the integrally formed motor rotating shaft 2 is manufactured by additive manufacturing, the motor rotating shaft 2 can be fixed on a processing machine tool through the cavity 23 arranged at the end of the transmission part 22, and the motor rotating shaft 2 is further processed. For example, after the integrally formed motor shaft 2 is manufactured by additive manufacturing, the outer surface of the mounting portion 21 needs to be further processed by grinding, so that in the case that the dimensional accuracy and the surface roughness of the outer surface of the mounting portion 21 meet the design requirements, one end of the motor shaft 2 can be clamped by a clamping jaw of a grinding machine, and a jacking rod of the grinding machine is jacked at the cavity 23 of the end face of the transmission portion 22, so that the motor shaft 2 is fixed to the grinding machine.

In some embodiments, as shown in fig. 2, the cavities 23 within the mounting portion 21 and the transmission portion 22 each extend in a first direction (the first direction being indicated by the arrow in fig. 2), i.e., such that the direction of extension of the cavities 23 is the same as the direction of extension of the mounting portion 21 and the direction of extension of the transmission portion 22. By setting the extending direction of the cavity 23 to be the same as the length direction of the mounting portion 21 and the transmission portion 22, the structure of the motor shaft 2 is simplified, the manufacturing difficulty of the motor shaft 2 is reduced, the weight of each part of the mounting portion 21 in the first direction is the same, the weight of each part of the transmission portion 22 in the first direction is the same, and the dynamic unbalance of the motor shaft 2 in rotation is reduced, so that the vibration and noise generated by the motor rotor 1 in the rotation process are reduced, and the service life of the motor shaft 2 is prolonged. Optionally, as shown in fig. 2, the mass center axis of the cavity 23 in the mounting portion 21 coincides with the mass center axis of the mounting portion 21, and the mass center axis of the cavity 23 in the transmission portion 22 coincides with the mass center axis of the transmission portion 22, so as to further reduce the dynamic unbalance degree of the motor shaft 2 in the rotating process, thereby reducing the vibration and noise generated by the motor rotor in the rotating process, and further prolonging the service life of the motor shaft 2.

In some embodiments, as shown in fig. 2, in a cross section perpendicular to the first direction, the outer edge dimension of the cavity 23 in the mounting portion 21 is larger than the outer edge dimension of the cavity in the driving portion 22, that is, in the case that the cavity 23 extends in the first direction (the first direction is shown by an arrow in fig. 2), the cross section of the cavity in the mounting portion 21 is set to be larger than the cross section of the cavity 23 in the driving portion 22, so that the inner space of the mounting portion 21 having a larger dimension is fully utilized in the case that the dynamic unbalance of the motor shaft 2 is reduced, thereby further reducing the weight of the motor shaft 2 and further reducing the weight of the motor rotor.

In some embodiments, as shown in fig. 2, at least one of the mounting portion 21 and the cavity 23 in the transmission portion 22 is a closed cavity, wherein the closed cavity is completely located inside the mounting portion 21 or the transmission portion 22 and is not communicated with the external space of the motor shaft 2, so that when the cavity is arranged in the motor shaft 2, the possibility that dust or liquid in the external space of the motor shaft 2 enters the closed cavity is reduced, the possibility that the inside of the motor shaft 2 is corroded is reduced, and the service life of the motor shaft 2 is prolonged. Optionally, the cavities 23 in the mounting portion 21 and the driving portion 22 are closed cavities. It should be noted that, through the cutting process or the casting process, the closed cavity cannot be set in the mounting portion 21 and the transmission portion 22 of the integrally formed motor shaft 2, specifically, through the cutting process, the cavity communicated with the external space of the motor shaft 2 needs to be obtained in the motor shaft 2 through the cutting process, then the opening of the cavity is closed by using the closed element through means of welding or splicing, and the like, the processing step is complex, and the integral forming of the motor shaft 2 cannot be realized, the integrity of the motor shaft 2 is poor, stress concentration is easily formed at the splicing position such as a welding seam, and further the service life of the motor shaft 2 is shortened, and after the motor shaft 2 with the closed cavity is obtained through casting, the core cannot be taken out from the motor shaft 2. The above problem can be overcome by additive manufacturing, and the motor shaft 2 can be integrally formed, so that the motor shaft 2 with a closed cavity can be directly machined while the integrity of the motor shaft 2 is improved, and in summary, a person skilled in the art can not set the closed cavity in the mounting portion 21 and the transmission portion 22 of the motor shaft 2 on the premise that the motor shaft 2 is integrally formed by additive manufacturing through cutting or casting.

Optionally, referring to fig. 1 and 2, a reinforcing rib 24 is disposed on a wall surface of the mounting portion 21 and/or the driving portion 22 adjacent to the cavity 23, and the reinforcing rib 24 extends from the wall surface toward the interior of the cavity 23, so that the structural strength of the motor shaft 2 is improved and the service life of the motor shaft 2 is further prolonged without affecting the shape of the outer surface of the motor shaft 2. Optionally, the reinforcing ribs 24 extend along the first direction, and the reinforcing ribs 24 are plural and are disposed in the cavity 23 at intervals around the first direction, so that the strength of the motor shaft 2 is further increased, and the service life of the motor shaft 2 is prolonged. It should be noted that, on the premise that those skilled in the art do not contemplate that the motor shaft 2 with the closed cavity may be manufactured by additive manufacturing and integral molding, those skilled in the art do not contemplate that the reinforcing ribs 24 are disposed in the closed cavity.

In some embodiments, as shown in fig. 3, the mounting portion 21 includes: a fitting portion 211 and a positioning portion 212. The squirrel-cage assembly 1 in fig. 1 is sleeved on the sleeved part 211, and the transmission part 22 is arranged at the end part of the sleeved part 211, alternatively, the transmission part 22 can be arranged at one end of the sleeved part 211 or at two ends of the sleeved part 211. The positioning portion 212 extends from the circumferential outer surface of the sleeve portion 211 to a second direction (the second direction is shown by a dashed arrow in fig. 3), wherein the axial outer surface of the positioning portion 212 may be a non-end outer surface of the positioning portion 212, and after the squirrel-cage assembly 1 is sleeved on the sleeve portion 211, the positioning portion 212 may abut against one end surface of the squirrel-cage assembly 1 in the first direction (the first direction is shown by a solid arrow in fig. 3), so as to limit the movement of the squirrel-cage assembly 1 relative to the sleeve portion 211 in the first direction. Wherein the second direction is substantially perpendicular to the first direction, i.e. the positioning portion 212 extends along an outer surface substantially perpendicular to the nesting portion 211, so that the size of the positioning portion 212 perpendicular to the nesting portion 211 is fully utilized, and the contact area between the positioning portion 212 and the squirrel cage assembly 1 is increased, so that the movement of the squirrel cage assembly 1 relative to the nesting portion 211 along the first direction is more reliably limited, the second direction is substantially perpendicular to the first direction, and it is understood that an included angle between the first direction and the second direction is allowed due to a manufacturing error, and a difference between the included angle between the first direction and the second direction and 90 degrees is small and a preset angle, for example, the preset angle is 5 degrees, and then the included angle between the first direction and the second direction is between 85 degrees and 95 degrees. It should be noted that, only one positioning portion 212 is provided on the circumferential outer surface of the sleeve portion 211, that is, the mounting portion 212 is only used to abut against one side of the squirrel cage assembly 1 along the first direction, so as to limit the movement of one side of the squirrel cage assembly 1 along the first direction, and the assembly between the squirrel cage assembly 1 and the sleeve portion 211 is not affected.

In some embodiments, as shown in fig. 3, the distance that the positioning portion 212 protrudes from the circumferential outer surface of the sleeve portion 211 is greater than a preset threshold, that is, in a cross section perpendicular to the first direction, the outer edge dimension of the positioning portion 212 is much greater than the outer edge dimension of the sleeve portion 211, so as to increase the contact area between the end surface of the squirrel-cage assembly 1 in the first direction and the positioning portion 212 in fig. 1, and further more reliably limit the movement of the squirrel-cage assembly 1 relative to the motor rotating shaft 2 in the first direction, where the preset threshold may be, for example, half the outer edge dimension of the squirrel-cage assembly 1, so as to limit the movement of the squirrel-cage assembly 1 in the first direction. It should be noted that, in the structure of the mounting portion 21 in which the outer edge dimension of the positioning portion 212 is significantly larger than the outer edge dimension of the fitted portion 211 is difficult to be formed by cutting or welding, specifically, the mounting portion 21 of the motor shaft 2 is formed by cutting, it is necessary to manufacture a blank having a shaft diameter not smaller than the shaft diameter of the positioning portion 212, and to cut the portion of the blank corresponding to the fitted portion 211 by cutting to a shaft diameter not smaller than the shaft diameter of the positioning portion 212 to a value slightly larger than or equal to the shaft diameter of the fitted portion 211, a large amount of metal material is consumed during cutting, and at the same time, since the cutting amount is large, in order to prevent overheating of the tool or breakage of the tool during cutting, it is necessary to process the fitted portion 211 by cutting a plurality of times, and the processing is complicated and time-consuming and labor-consuming. The sleeve part 211 and the positioning part 212 of the mounting part 21 are respectively processed, then the sleeve part 211 is fixedly connected with the positioning part 212 through welding, a welding seam is generated between the sleeve part 211 and the positioning part 212, the integrity of the mounting part 21 is poor, and stress on the mounting part 21 of the motor rotating shaft 2 can generate stress concentration at the welding seam, so that the service life of the motor rotating shaft 2 is shortened. The positioning portion 212 is integrally formed by additive manufacturing, so that the above problems occurring when the positioning portion 212 is manufactured by cutting or welding can be overcome, and in summary, the person skilled in the art will not design the mounting portion of the motor shaft as the structure of the mounting portion 21 provided in the present embodiment on the premise that the person skilled in the art manufactures the mounting portion 21 of the motor shaft 2 by cutting or welding, and does not think that the mounting portion 21 of the motor shaft 2 can be obtained by additive manufacturing integrally.

In some embodiments, as shown in fig. 3, the outer surface of the sleeving part 211 is provided with a heat dissipation air duct 213, the length direction of the heat dissipation air duct 213 is substantially parallel to the first direction (the first direction is shown by a solid arrow in fig. 3), after the squirrel-cage assembly 1 in fig. 1 is sleeved on the mounting part 21, the air flow flowing in the heat dissipation air duct 213 can cool the squirrel-cage assembly 1, so that the possibility of damage of the squirrel-cage assembly 1 due to overheat is reduced, the service life of the squirrel-cage assembly 1 is prolonged, and meanwhile, compared with a related heat dissipation scheme in which heat dissipation holes are arranged in a motor rotor, the weight of the motor rotating shaft 2 is further reduced by arranging the heat dissipation air duct 213. The length direction of the heat dissipation air channel 213 may be a direction of the heat dissipation air channel 213 having a maximum size, and the length direction of the heat dissipation air channel 213 is substantially parallel to the first direction, which may be understood as allowing an included angle between the length direction of the heat dissipation air channel 213 and the first direction due to a manufacturing error, and the included angle between the length direction of the heat dissipation air channel 213 and the first direction is smaller than a preset angle, which may be 5 degrees.

Optionally, as shown in fig. 3, the heat dissipation air duct 213 penetrates through two end surfaces of the positioning portion 212 along the first direction, so as to extend the length of the heat dissipation air duct 213, further enhance the heat dissipation effect of the heat dissipation air duct on the squirrel cage assembly 1, improve the integration degree of the positioning portion 212 and the mounting portion 21, and improve the overall strength of the motor shaft, so as to further extend the service life of the squirrel cage assembly 1. It should be noted that, the structure that the heat dissipation air duct 213 penetrates through the two end surfaces of the positioning portion along the first direction is difficult to be achieved through cutting, specifically, the heat dissipation air duct 213 penetrates through the positioning portion 212 through cutting, and a through-hole penetrating through the two end surfaces of the positioning portion 212 along the first direction needs to be formed in the positioning portion 212 so that a cutting tool penetrates through the positioning portion 212, so that manufacturing difficulty of the positioning portion 212 is increased, structural strength of the positioning portion 212 is reduced, and reliability of the positioning portion 212 in limiting movement of the squirrel cage assembly 1 relative to the sleeve portion 211 along the first direction is reduced. And respectively process the locating part 212 and the cover portion 211 that establishes with the heat dissipation wind channel 213 to fix the locating part 212 in the circumference external surface of cover portion 211 through the welding, not only reduced the wholeness of installation department 21, can produce stress concentration in the welding seam department of establishing between portion 211 and the locating part 212, reduced the life of installation department 21, simultaneously, owing to cover portion 211 is provided with the heat dissipation wind channel 213, the area of contact between portion 211 and the locating part 212 is less, has reduced the length of cover portion 211 and locating part 212, thereby reduced the fixed force between cover portion 211 and the locating part 212, further reduced the overall structure intensity of installation department 21. The mounting portion 21 of the motor shaft 2 with the heat dissipation air duct 213 penetrating the positioning portion 212 is integrally formed by additive manufacturing, so that the problems occurring in the cutting process or the welding process can be overcome. In summary, on the premise that the person skilled in the art manufactures the mounting portion 21 of the motor shaft 2 by cutting or welding, and does not think that the mounting portion 21 of the motor shaft 2 can be obtained by additive manufacturing integrated molding, the person skilled in the art does not design the mounting portion of the motor shaft as the structure of the mounting portion 21 provided in the present embodiment.

In some embodiments, the cooling air channels 213 are formed by spaced cooling ribs around the outer surface of the sleeve 211, such that the cooling ribs carry air flow during high speed rotation following the motor shaft 2, thereby cooling the squirrel cage assembly 1. In other embodiments, the fan blades are disposed inside the heat dissipation air channel 213, and during the rotation of the motor shaft 2, the fan blades also rotate together and drive the air to move along the length direction of the heat dissipation air channel 213, so that the air is driven to move along the length direction of the heat dissipation air channel 213 and cool the rotor core in fig. 1 without additional air driving devices. Optionally, the fan blades are disposed on a side opposite to the side of the positioning portion 212 on which the squirrel cage assembly 1 is disposed, so that the heat dissipation effect on the squirrel cage assembly 1 is further enhanced without reducing the length of the portion of the heat dissipation air duct 213 that contacts the squirrel cage assembly 1.

In some embodiments, the motor shaft 2 further includes a counterweight mounting structure for mounting a dynamic counterweight at a corresponding position, so as to reduce dynamic unbalance of the motor shaft 2, further reduce noise and vibration generated in the rotation process of the motor shaft 2, and prolong the service life of the motor shaft 2. The weight mounting structure may be any structure capable of mounting a dynamic weight, for example, the weight mounting structure may be a threaded hole to which the dynamic weight is fixed by a bolt, so that the dynamic weight is fixed to the motor shaft 2. Meanwhile, the weight mounting structure may be provided at any position where the rotational inertia of the motor shaft 2 can be adjusted, for example, the dynamic balance mounting structure may be provided at the surface of the positioning portion 212. Optionally, the motor rotating shaft 2 is further provided with a transmission key, and the transmission key is used for fixing accessories of other motor rotors needing to be driven by the motor rotating shaft 2 and the motor rotating shaft 2 in the circumferential direction, so that the motor rotating shaft 2 can drive the accessories to rotate together, and the transmission key is further used for fixing the squirrel-cage assembly 1 and the motor rotating shaft 2 with the circumferential direction, so that the rotor of the motor can drive the motor rotating shaft 2 to rotate together, wherein the transmission key is integrally formed in the motor rotating shaft 2 through material increase manufacturing, has larger structural strength and can transmit larger torque.

In some embodiments, as shown in fig. 3, bearing sealing portions 25 are further disposed at both ends of the mounting portion 21, specifically, a transmission portion 22 is disposed at both ends of the mounting portion 21 in the first direction, the transmission portion 22 is rotatably connected with the housing of the motor, and a bearing is disposed between the transmission portion 22 and the housing of the motor 1. The bearings are lubricated with grease, and the two bearings are respectively abutted against the bearing sealing portions 25 at both ends of the mounting portion 21, so that the loss of grease in the bearings is reduced, and the wear of the bearings is reduced. Optionally, the bearing sealing portion 25 is a labyrinth sealing ring, specifically, an end surface of the labyrinth sealing ring, which is used for being abutted to a bearing, is provided with a plurality of annular sealing teeth which are sequentially arranged, a series of interception gaps and expansion cavities are formed between the teeth, and a throttling effect is generated when a sealed medium passes through the gaps of the tortuous labyrinth to prevent grease from being lost. It should be noted that, the bearing sealing portion 25 is integrated in the portion of the motor shaft 2 during the process of manufacturing the motor shaft 2 by integrally forming the additive manufacturing, so as to further increase the integrity of the motor shaft 2, and further increase the structural strength of the motor shaft 2.

In some embodiments, in combination with fig. 4 and 5, the squirrel cage assembly 1 comprises: rotor core 10, guide bars 20, and end rings 30. The rotor core 10 extends in a first direction and has (the first direction is shown by the arrow in fig. 4 and 5) opposite first and second end faces 11, 12, and the rotor core 10 is sleeved on at least part of the mounting portion 21. The rotor core 10 is made of a metallic material having high saturation induction intensity to increase the intensity of electromagnetic induction, and is made of a silicon steel sheet. Further, the rotor core 10 is fitted to the fitting portion 211, and the positioning portion 212 can be abutted against one end surface of the rotor core 10 in the first direction. The positioning portion 212 is specifically abutted with the rotor core 10, or abutted with the end ring 30 of the squirrel cage assembly 1, and can be set according to actual requirements. The plurality of guide bars 20 are arranged at intervals along the circumferential direction of the rotor core 10, and penetrate through the rotor core 10, namely, the guide bars 20 are arranged at intervals around the first direction, each guide bar 20 penetrates through the rotor core 10,

The end rings 30 are two, and the two end rings 30 are respectively arranged at two sides of the rotor core 10 and fixedly connected with the guide bars 30. Specifically, the two end rings 30 are a first end ring 301 and a second end ring 302, respectively. The first end ring 301 is located outside the rotor core 10, i.e. the first end ring 301 is arranged outside the space enclosed by the outer contour of the rotor core 10. The first end ring 301 is arranged close to the first end face 11 with respect to the second end face 12 in the first direction, i.e. the first end ring 301 is spaced from the first end face 11 less than the first end ring 301 is spaced from the second end face 12. The second end ring 302 is located outside the rotor core, i.e. the second end ring 302 is arranged outside the space enclosed by the outer contour of the rotor core 10. The second end ring 302 is arranged close to the second end face 12 with respect to the first end face 11 in the first direction, i.e. the second end ring 302 is spaced from the second end face 12 less than the second end ring 302 is spaced from the first end face 11.

Specifically, two end rings are obtained through additive manufacturing, the end rings are fixedly connected with the guide bars, specifically, a first end ring is fixedly connected with a part of the guide bars, which extends out of the first end face of the rotor core, and a second end ring is fixedly connected with a part of the guide bars, which extends out of the second end face of the rotor core. In the additive manufacturing process, materials for manufacturing the first end ring and the second end ring are melted and solidified, so that acting force for enabling the first end ring to be fixedly combined with the conducting strip and enabling the second end ring to be fixedly combined with the conducting strip is formed between contact surfaces of the first end ring and the conducting strip and between contact surfaces of the second end ring and the conducting strip, the first end ring and the second end ring are not manufactured through the additive, then the first end ring and the second end ring are respectively fixed on the conducting strip, and good integration is achieved between the two end rings and the conducting strip. Therefore, the end ring and the guide bar are prevented from being fixedly connected in a welding mode, and meanwhile, the problem of insufficient welding is avoided.

In some embodiments, the end surfaces of the guide bars extending out of the rotor core are fixedly connected with the end ring, and the spacing between the end ring and the end surface of the rotor core is smaller than a preset value. That is, one end of the guide bar 20 protrudes from the first end face 11 of the rotor core 10, the other end of the guide bar 20 opposite to the end protruding from the first end face 11 protrudes from the second end face 12, and both ends of the guide bar 20 are respectively fixed to the end ring 30. And the distance between the first end ring 301 and the first end face 11 is smaller than a preset value, and the distance between the second end ring 302 and the second end face 12 is smaller than a preset value. By making the distance between the first end face 11 and the first end ring 301 smaller than a preset value and making the distance between the second end face 12 and the second end ring 302 smaller than a preset value, the movement of the rotor core 10 along the first direction relative to the first end ring 301 and the second end ring 302 is limited within a small range by the first end ring 301 and the second end ring 302, so that the integrity of the squirrel-cage assembly is improved, the natural frequency of the squirrel-cage assembly is optimized, resonance with external excitation is not easy to occur in the operation process of the squirrel-cage assembly, vibration is reduced, and the service life of the squirrel-cage assembly is prolonged.

Specifically, in the first direction, the distance between each end face and the corresponding end ring is small and a preset value, specifically, the distance between the first end face and the first end ring is smaller than the preset value, and the distance between the second end face and the second end ring is smaller than the preset value, and optionally, the preset value may be 5 mm. The distance between the end face of the rotor core and the corresponding end ring is smaller than a preset value, so that the movement of the rotor core relative to the end ring along the first direction is limited in a small range through the end ring, the integrity of the squirrel-cage assembly is improved, the natural frequency of the squirrel-cage assembly is optimized, the squirrel-cage assembly is not easy to resonate with external excitation in the operation process, vibration is reduced, and the service life of the squirrel-cage assembly is prolonged. Meanwhile, the distance between the end face of the rotor core and the corresponding end ring is smaller than a preset value, so that noise generated in the operation process of the squirrel cage assembly can be reduced, and the principle of noise reduction is described below. The distance between the end ring of the related squirrel cage assembly and the end face of the rotor core is larger, the length of the conducting bars exposed in the air between the end ring and the end face of the rotor core is longer, and in the rotating process of the squirrel cage assembly, the conducting bars of the part continuously stir the air, so that larger noise is generated; the end ring of the squirrel-cage assembly and the end face of the corresponding rotor core are smaller than a preset threshold, the length of the conducting bars exposed in the air between the end ring and the end face of the rotor core is shorter, and in the rotating process of the squirrel-cage assembly, the air stirring capacity of the conducting bars is weakened, so that noise generated in the operation process of the squirrel-cage assembly is reduced. It should be noted that, in the first direction, the design of the small distance between each end face and the corresponding end ring and the preset value can only be obtained by the additive manufacturing method, and specific reasons are described in other embodiments, so that the description is omitted herein.

In some embodiments, the predetermined value is 5 millimeters, i.e., the first end ring 301 is less than 5 millimeters from the first end face 11 and the second end ring 302 is less than 5 millimeters from the second end face 12. Therefore, the distance of the rotor core 10 between the first end ring 301 and the second end ring 302 along the first direction is limited within 10 millimeters through the first end ring 301 and the second end ring 302, so that the integrity of the squirrel-cage assembly is improved, the natural frequency of the squirrel-cage assembly is optimized, resonance with external excitation is not easy to occur in the operation process of the squirrel-cage assembly, vibration is reduced, and the service life of the squirrel-cage assembly is prolonged.

In some embodiments, the first end ring 301 abuts the first end face 11 and the second end ring 302 abuts the second end face 12, i.e., the first end ring 301 is spaced from the first end face 11 and the second end ring 302 is spaced from the second end face 12 by zero, such that the rotor core 10 is prevented from moving in a first direction relative to the first end ring 301 and the second end ring 302 by the first end ring 301 and the second end ring 302, thereby further reducing vibrations caused by movement of the rotor core 10 relative to the first end ring 301 and the second end ring in the first direction during operation of the squirrel cage assembly, and further extending the useful life of the squirrel cage assembly. Meanwhile, the first end ring 301 is abutted against the first end face 11, and the second end face 302 is abutted against the second end face 12, so that the length of the guide bars exposed to air between the end ring and the corresponding end face of the rotor core can be further reduced, and even the guide bars exposed to air do not exist between the end ring and the corresponding end face of the rotor core, and therefore the air stirring capacity of the guide bars of the portion is further reduced, and noise generated in the rotating process of the squirrel cage assembly is further reduced.

In some embodiments, as shown in connection with fig. 6 and 7, both end rings 30 have mounting slots 31, the mounting slots 31 being used to receive portions of the bars 20 that are connected to the end rings 30. I.e. the first end ring 301 and the second end ring 302 each have a mounting groove 31, the mounting groove 31 being adapted to receive one end of the conductor 20 extending beyond the first end face 11 in fig. 4 and the other end of the conductor 20 extending beyond the second end face 12 in fig. 5. As shown in fig. 6, taking the first end ring and the guide bar adjacent to the first end ring as an example, specifically, the first end ring 301 has a mounting groove 31, and one end of the guide bar 20 extending out of the first end face 11 extends into the mounting groove 31 of the first end ring 301. By providing the mounting grooves 31 in the first end ring 301 and the second end ring 302, the contact area between the first end ring 301 and the conductor 20, and the contact area between the second end ring 302 and the conductor 20 are increased, thereby enabling the first end ring 30 to be more firmly fixed to the conductor 20, and the second end ring 302 to be more firmly fixed to the conductor 20. Alternatively, the length of the guide bar 20 extending into the mounting slot 50 is between 5 mm and 10 mm.

In some embodiments, as shown in fig. 6, the portion of the guide bar 20 located within the mounting groove 31 is provided with a first spacing structure 201, and the walls of the first end ring 301 and the second end ring 302 adjacent to the mounting groove 31 have spacing portions 312. Specifically, the mounting groove 31 includes a supporting groove 311 and a limiting portion 312, the limiting portion 312 and the supporting groove 311 are formed into a whole, the supporting groove 311 has an open end surface, so the supporting groove 311 is disposed near the end surface of the end ring 30, and an extending direction of the supporting groove 311 and an extending direction of the limiting portion 312 form a preset included angle, that is, the extending direction of the supporting groove 311 is different from the extending direction of the limiting portion 312, or an extending direction of at least part of the structure of the limiting portion 312 is different from the extending direction of the supporting groove 311, and the preset included angle may be 30 °, 60 ° or 90 °. It should be noted that, the limiting portion 312 extends to a first position, and the first position is spaced from the opening end surface of the supporting slot 311 by a preset distance. The first position may be considered as a position to which at least part of the stopper 312 extends, and the part of the stopper 312 at this position may be one surface or one point. The first position where the limiting portion 312 extends is spaced from the opening end face of the supporting groove 311 by a preset distance, that is, the setting position of the limiting portion 312 on the supporting groove 311 is clear, so that the limiting portion 312 does not have the opening end face or does not penetrate through the opening end face of the supporting groove 311, that is, in the mounting groove 31, the limiting portion 312 has a feature different from the form of the supporting groove 311 and away from the opening end face, so as to limit the movement of the end ring 30 relative to the guide bar 20 in the depth direction, and make the guide bar 20 and the end ring 30 firmly connected. In the structure shown in fig. 6, the preset included angle is 90 degrees, and the extending direction of the supporting slot 311 is a straight line and parallel to the depth direction of the end ring 30, and the limiting portion 312 is disposed on the side surface of the supporting slot 311. The limiting portion 312 abuts against the first limiting structure 201 to limit the movement of the first end ring 301 relative to the guide bar 20, and the movement of the second end ring 302 relative to the guide bar 20.

The following describes the design concept of the supporting groove and the limiting portion provided in this embodiment. By limiting the positions and structures of the limit part and the support part, the mounting groove has an irregular shape, and if the mounting groove adopts a cutting or pouring method, the mounting groove is poor in economy or cannot be molded, and is not applicable. Specifically, the cutter is manufactured into the shape of the mounting groove, the end ring is drilled, and the finally obtained drilling shape is different from the cutter shape due to the fact that the cutter exits after drilling, namely, the mounting groove cannot be obtained through the cutter. Or, the end ring of the present application is obtained by casting, and it is necessary to manufacture the same core as the mounting groove first, then place the core in the end ring mold and cast the core, so that the end ring after cast molding cannot take out the core, and the end ring with the mounting groove of the present application cannot be obtained. The possibility of the occurrence of the problems can be reduced through additive manufacturing, specifically, the end ring is directly and fixedly connected with the conducting bars in the additive manufacturing process, and after the end ring is obtained through additive manufacturing, the end ring is fixed on the conducting bars, so that the limiting structure of the end ring is matched with and abutted against the structure of the end part of the conducting bars. According to the structural shape of the end portion of the guide bar, the end ring with the mounting groove is formed by gradually increasing the material on the surface of the end portion of the guide bar, so that the supporting groove and the limiting portion in the application can be obtained to limit the movement of the end ring relative to the guide bar. In summary, based on the manufacturing method of cutting or pouring the end ring in the prior art, a person skilled in the art cannot think of setting the limiting structure of the present application in the end ring by means of additive manufacturing, and further cannot think of realizing the limiting of the end ring by setting the supporting portion and the limiting portion.

The beneficial effects of the squirrel cage assembly to which the end ring of the embodiments of the present application are applied are described below. The fixed connection between the guide bars and the end ring may be insufficient, for example, welding in the related art is insufficient, or in the process of manufacturing the end ring fixed with the guide bars through additive manufacturing, due to insufficient melting and other reasons, acting force for fixedly connecting the end ring and the guide bars is insufficient, and further the end ring is separated from the guide bars under the action of external load in the operation process of the squirrel cage assembly. Through setting up spacing portion for the conducting bar can prevent that the end ring from taking place relative motion with the conducting bar under the effort of spacing portion mutual butt, fly out from the conducting bar, set up the security that spacing portion has improved the squirrel cage subassembly, thereby improved the connection steadiness of conducting bar and end ring. Through set up supporting groove and spacing portion on the end ring for the conducting bar can stretch into limit structure in and with spacing portion butt, with the motion of the relative conducting bar of restriction end ring, increased the connection stability of conducting bar and end ring. Meanwhile, by providing the first limiting structure 201 and the limiting portion 312, the contact area between the end ring and the guide bar can be further increased, so that the end ring can be more firmly fixed to the guide bar.

In some embodiments, as shown in fig. 6, the first limiting structure 201 is a limiting groove, the limiting portion 312 is a limiting boss, and at least a portion of the limiting boss is located in the first limiting structure 201 (limiting groove), so that the end ring 30 is prevented from flying out of the guide bar 20 by an abutment force between the first limiting structure 201 (limiting groove) and the limiting portion 312 (limiting boss), and safety of the squirrel cage assembly is improved.

In some embodiments, as shown in fig. 7, the first limiting structure 201 is a limiting boss, and the limiting portion 312 limits a slot, that is, the slot area of the limiting structure 31 is increased on the basis of the supporting slot 311, and the limiting slot extends from the side surface of the supporting slot 311 to a first position, where the first position is a position other than the supporting slot 311. The limiting groove shown in fig. 7 is arranged along the extending direction perpendicular to the supporting groove 311, and the end of the guide bar 20 is provided with an abutting part 21 with the same structure as the limiting groove. In this way, the end of the conducting bar 20 can effectively abut against the limiting groove, and the movement of the end ring 30 relative to the conducting bar 20 can be effectively limited through the abutting force of the limiting groove and the conducting bar 20, so that the connection stability of the conducting bar 20 and the end ring 30 is enhanced. Compared with the arrangement of only the supporting groove 311 which is abutted against the guide bar 20, the arrangement of the limiting groove further increases the contact area between the end ring 30 and the guide bar 20.

In some embodiments, as shown in fig. 8, the rotor core 10 is provided with a positioning groove 13, and the positioning groove 13 extends from the first end face 11 to the second end face 12 in fig. 5. A portion of the guide bar 20 is positioned in the positioning groove 13, thereby facilitating the assembly of the guide bar 20 with the rotor core 10. Optionally, the outer contour of the positioning groove 13 in the cross section perpendicular to the first direction coincides with the outer contour of the guide bar 20 in the cross section perpendicular to the first direction, thereby further facilitating the assembly between the guide bar 20 and the rotor core 10. Optionally, the number of the positioning slots 13 is equal to the number of the guide bars 20, and are disposed at intervals around the rotor core 10 in the first direction.

The embodiment of the invention also provides a manufacturing method of the motor rotor, as shown in fig. 9, comprising the following steps:

s1: processing to obtain a squirrel cage assembly, wherein the processing comprises additive manufacturing and subtractive manufacturing, and the subtractive manufacturing can be any one or more of a plurality of processing modes such as turning, milling, planing, grinding and the like;

s2: the motor rotating shaft is obtained through additive manufacturing;

s3: the squirrel cage assembly is sleeved on the motor rotating shaft.

As shown in fig. 10, step S1 includes:

step S101, machining to obtain a guide bar and a rotor core, wherein the rotor core has two end faces opposite in the first direction.

The guide bar can be obtained by any processing method, and the processing method of the guide bar can be forging or rolling forming. The rotor core is made of a metal material with high saturation induction intensity, which is used for enhancing the electromagnetic induction intensity of the squirrel cage assembly, and the metal material can be silicon steel. Optionally, the rotor core is formed by laminating and fixing a plurality of layers of metal sheets with high saturation magnetic induction intensity, and the metal sheets can be silicon steel sheets.

Step S102, penetrating the guide bars through the rotor core along the first direction and protruding outwards from the two end faces.

Specifically, the guide bar is provided with a first end and a second end which are opposite along a first direction, the first end of the guide bar protrudes out of the first end face of the rotor core after the guide bar penetrates through the rotor core, and the second end of the guide bar protrudes out of the second end face of the rotor core. The guide bars are arranged at intervals circumferentially around the first direction, and penetrate through the rotor core along the first direction.

Step S103, obtaining a corresponding end ring close to each end face through additive manufacturing.

Specifically, two end rings are manufactured through additive manufacturing, wherein the end ring close to the first end face of the rotor core is a first end ring, the end ring close to the second end face of the rotor core is a second end ring, namely, the distance between the first end ring and the first end face is smaller than that between the second end ring and the first end face, and the distance between the second end ring and the second end face is smaller than that between the second end ring and the first end face.

The end rings are fixedly connected with the guide bars, specifically, the first end ring is fixedly connected with a part of the guide bars, which extends out of the first end face of the rotor core, and the second end ring is fixedly connected with a part of the guide bars, which extends out of the second end face of the rotor core. It should be noted that, the first end ring and the second end ring are fixedly connected with the conducting bars in the additive manufacturing process, rather than after the first end ring and the second end ring are obtained through additive manufacturing, the first end ring and the second end ring are respectively fixed on the conducting bars, and good integration is achieved between the two end rings and the conducting bars.

The principle by which the pitch of the rotor core to the corresponding end ring can be reduced using the additive manufacturing method is described below. In the manufacturing method of the related squirrel-cage assembly, the rotor core, the guide bars and the end rings are required to be obtained firstly, then the rotor core, the guide bars and the end rings are spliced at preset positions, so that the squirrel-cage assembly is obtained, in the assembling process, the sizes of the rotor core, the guide bars and the end rings cannot be changed, the distance between the end face of the rotor core and the corresponding end rings is influenced by manufacturing errors of the rotor core, manufacturing errors of the end rings and assembling errors, the distance between the end face of the rotor core and the corresponding end rings can float in a larger range, the distance between the end face of the rotor core and the corresponding end rings is required to be larger, so that assembling interference between the rotor core and the end rings is prevented, and meanwhile, in the manufacturing method of the related squirrel-cage assembly, the end rings and the guide bars are fixed through welding, and a larger distance is required between the end rings and the end face of the rotor core in order to reduce the influence of high temperature generated during welding. In the manufacturing method of the squirrel-cage assembly provided by the embodiment of the invention, the guide bars and the rotor core are assembled, and then the two end rings corresponding to the two end faces of the rotor core are manufactured through additive manufacturing according to the actual positions of the end faces of the rotor core. The end ring is manufactured by taking the actual position of the end face of the rotor core as a reference, so that the influence of manufacturing errors of the rotor core and assembly errors of the rotor core and the guide bars on the distance between the end face of the rotor core and the corresponding end ring is reduced, and the distance between the end face of the rotor core and the corresponding end ring is mainly influenced by the size of the end ring and the size error of the end ring; meanwhile, the end ring is manufactured through additive manufacturing, the size of the end ring can be adaptively adjusted according to the actual position of the end face of the rotor core, and the additive manufacturing is a manufacturing method with higher precision, namely, the size of the end ring can be adaptively adjusted according to the actual position of the end face of the rotor core, and the size error of the end ring is smaller, so that the distance between the end face of the rotor core and the corresponding end ring floats in a smaller range, and the distance between the end face of the rotor core and the corresponding end ring is reduced on the premise that the rotor core and the end ring do not interfere in assembly. It should be noted that, fixing the conductive bars and the end ring by welding requires consuming solder and soldering flux, and the solder is generally silver solder with relatively high price, and forming the end ring directly on the conductive bars by additive manufacturing to solidify the end ring with the conductive bars, thereby saving the solder and soldering flux and reducing the cost of consumable materials used in the manufacturing process of the squirrel cage assembly.

In the processing process of the squirrel cage assembly, after the guide bars and the rotor cores are processed and assembled, the end rings are manufactured according to the actual positions of the end faces of the rotor cores, so that the influence of manufacturing errors of the rotor cores and the guide bars on the distance between the end faces of the rotor cores and the corresponding end rings is reduced, meanwhile, the end rings are manufactured through additive manufacturing, the size of the end rings can be adaptively adjusted according to the actual positions of the rotor cores, the size of the end rings is enabled to have higher precision, the floating range of the distance between the end faces of the rotor cores and the corresponding end rings is reduced, and the distance between the end faces of the rotor cores and the corresponding end rings is enabled to be smaller than a preset value on the premise that the rotor cores and the end rings do not interfere in assembly. The distance between the end face of the rotor core and the corresponding end ring is smaller than a preset value, so that the movement of the rotor core along the first direction relative to the end ring is limited in a small range through the end ring, the integrity of the squirrel-cage assembly is improved, the natural frequency of the squirrel-cage assembly is optimized, resonance is not easy to occur with external excitation in the operation process of the squirrel-cage assembly, vibration is reduced, and the service life of the squirrel-cage assembly is prolonged. Meanwhile, the distance between the end face of the rotor core and the corresponding end ring is smaller than a preset threshold value, and noise generated in the operation process of the squirrel cage assembly can be reduced.

In some embodiments, the end rings may be machined from any order in the first direction by additive manufacturing. Optionally, along the first direction, forming an end ring corresponding to the end surface by additive manufacturing from the end of the guide bar to a preset position close to the corresponding end surface, wherein the distance between the preset position and the first end surface is smaller than a preset value. Specifically, along a first direction, forming a first end ring corresponding to the first end surface through additive manufacturing from the end part of the guide bar extending out of the first end surface to a preset position close to the first end surface; and forming a second end ring corresponding to the second end surface through additive manufacturing from the preset position, which is close to the second end surface, of the end part, which extends out of the second end surface, of the guide bar along the first direction. Optionally, in the first direction, an end ring corresponding to the end face is formed by additive manufacturing from an end face of the rotor core toward an end portion of the bar. Specifically, in a first direction, forming a first end ring corresponding to the first end face by additive manufacturing from the first end face of the rotor core toward the end of the portion of the bar extending from the first end face; in the first direction, the second end face corresponding to the second end face is formed by additive manufacturing from the second end face of the rotor core to the end part of the guide bar, which extends out of the second end face.

In some embodiments, as shown in fig. 11, the manufacturing method of the squirrel cage assembly provided in this embodiment is different from the manufacturing method of the squirrel cage assembly shown in fig. 1 in that step S103 in fig. 10 includes:

step S201, forming a corresponding end ring by additive manufacturing from each end face outwards along the first direction.

Specifically, along a first direction, a first end ring is manufactured by additive manufacturing from a first end face of the rotor core facing away from the first end face, and a second end ring is manufactured by additive manufacturing from a second end face of the rotor core facing away from the second end face. The end part of the rotor core is directly used as the initial base surface for additive manufacturing, so that the distance between the end ring obtained through additive manufacturing and the end surface of the corresponding rotor core is zero, namely, the end ring can be abutted against the end surface of the corresponding rotor core, thereby further reducing the movement of the rotor core relative to the end ring along the first direction, further reducing the vibration caused by the movement of the rotor core relative to the end ring along the first direction in the operation process of the squirrel cage assembly, and further prolonging the service life of the squirrel cage assembly.

Wherein one side of the end ring is located outside the bars, i.e. the end ring obtained by additive manufacturing, extends in a first direction from the corresponding end face of the rotor core in a direction away from the end face until it extends beyond the corresponding end of the bars. Specifically, the first end ring obtained by additive manufacturing extends from the first end face of the rotor core to a direction far away from the first end face along a first direction until the first end extends to exceed the first end of the guide bar, wherein the first end is the end part of the guide bar protruding out of the first end face; and the second end ring is manufactured by additive, extends from the second end face of the rotor core to a direction far away from the second end face along the first direction, and extends to the end part exceeding the second end of the guide bar and being the part of the guide bar protruding out of the second end face. The first end ring extends to a first preset position beyond the first end of the guide bar along the first direction, and the distance between the first preset position and the first end of the guide bar is preset, for example, the preset distance can be 5 mm; the second end ring extends in the first direction to a second predetermined position beyond the second end of the guide bar, the second predetermined position being spaced a predetermined distance from the second end of the guide bar, which may be, for example, 5 millimeters. The end ring manufactured by additive manufacturing has a force for fixing the end ring and the guide bars between contact surfaces of the end ring and the guide bars due to melting of materials, and the larger the contact area between the end ring and the guide bars is, the more stable the connection between the end ring and the guide bars is. The end ring extends to the outer side of the conducting bars from the end part of the rotor core along the first direction, and the size of the part of the conducting bars extending out of the end face of the rotor core along the first direction is fully utilized, so that the contact area between the end ring and the conducting bars is increased, the connection between the end ring and the conducting bars is more stable, and meanwhile, the conductivity between the conducting bars and the end ring is improved.

Additive manufacturing may be a manufacturing process in which successive layers of material are provided on top of each other to build up a three-dimensional part layer by layer, with adjacent layers of material being melted between them to form an integral part. It should be understood that additive manufacturing in embodiments of the present invention refers to manufacturing by adding material primarily during manufacturing, but may also be performed in a specific manufacturing process with additional processing steps, such as layer addition processing, layer subtraction processing, or hybrid processing. Additive manufacturing may be by any one of fused deposition modeling, selective laser sintering, stereolithography, electron beam sintering, and the like.

In some embodiments, to more clearly illustrate the process of additive manufacturing to obtain an end ring, the process of manufacturing an end ring is illustrated below by way of example in connection with fig. 12 in which the process of additive manufacturing is performed by a selective laser sintering method, and it should be understood by those skilled in the art that end rings may also be obtained by other additive manufacturing methods. The consolidation between the end ring and the conducting bar obtained by the selective laser sintering method is good, so that the squirrel cage assembly has high structural strength.

As shown in fig. 12, the manufacturing method of the squirrel-cage assembly provided in the present embodiment is different from the manufacturing method of the squirrel-cage assembly shown in fig. 11 in that step S201 in fig. 11 includes:

step S301: and spraying metal powder on the end face of the rotor core, and sintering the metal powder to form a first section layer fixedly connected with the guide bar.

Specifically, according to the shape of the end ring, a predetermined portion of the metal powder is melted by laser, and the melted metal powder is solidified to form a first cross-sectional layer. Meanwhile, in the process of sintering the metal powder by laser, the metal powder near the conducting bar is melted, and the metal powder at the part is solidified and then is solidified with the outer surface of the conducting bar into a whole, so that the first section layer is fixedly connected with the conducting bar. In this step, the metal powder is melted by the laser, but the thickness of the sprayed metal powder is thin, and only the metal powder in the preset part is required to be melted, so that the time of the laser acting on the metal powder is short, and the influence of the heat generated by the laser on the end part of the rotor core is small or negligible.

Step S302, spraying metal powder on the first cross-sectional layer and sequentially forming additional cross-sectional layers in order to solidify the first cross-sectional layer and each additional cross-sectional layer to form an end ring.

Specifically, after the sintering of the first section layer is completed, according to the shape of the end ring, a preset part of metal powder is melted by laser, the melted technical powder is solidified to form another section layer, in the process of melting the metal powder, the section layer is solidified with the first section layer, meanwhile, the metal powder near the conducting bar is melted, and the part of metal powder is solidified and integrated with the outer surface of the conducting bar, so that the other section layer is fixedly connected with the conducting bar. And repeating the steps of spraying metal powder on the newly formed section layer from the end surface of the rotor core to the direction away from the end surface along the first direction, sintering the metal powder into another section layer by laser according to the shape of the end ring until the newly formed section layer reaches the outer side of the conducting bar, thereby obtaining the end ring by additive manufacturing.

It should be noted that, one side of the end ring is located at the outer side of the guide bar, i.e. the end ring obtained by additive manufacturing, extends from the corresponding end face of the rotor core in the first direction away from the end face until reaching beyond the corresponding end of the guide bar. Specifically, the first end ring obtained by additive manufacturing extends from the first end face of the rotor core to a direction far away from the first end face along a first direction until the first end extends to exceed the first end of the guide bar, wherein the first end is the end part of the guide bar protruding out of the first end face; and the second end ring is manufactured by additive, extends from the second end face of the rotor core to a direction far away from the second end face along the first direction, and extends to the end part exceeding the second end of the guide bar and being the part of the guide bar protruding out of the second end face. The first end ring extends to a first preset position beyond the first end of the guide bar along the first direction, and the distance between the first preset position and the first end of the guide bar is preset, for example, the preset distance can be 5 mm; the second end ring extends in the first direction to a second predetermined position beyond the second end of the guide bar, the second predetermined position being spaced a predetermined distance from the second end of the guide bar, which may be, for example, 5 millimeters. The end ring manufactured by additive manufacturing has a force for fixing the end ring and the guide bars between contact surfaces of the end ring and the guide bars due to melting of materials, and the larger the contact area between the end ring and the guide bars is, the more stable the connection between the end ring and the guide bars is. The end ring extends to the outer side of the conducting bars from the end part of the rotor core along the first direction, and the size of the part of the conducting bars extending out of the end face of the rotor core along the first direction is fully utilized, so that the contact area between the end ring and the conducting bars is increased, the connection between the end ring and the conducting bars is more stable, and meanwhile, the conductivity between the conducting bars and the end ring is improved.

In some embodiments, after one end ring is manufactured by additive manufacturing, the other end ring is manufactured by additive manufacturing, and after the end ring corresponding to the one end surface is manufactured, a limiting force is applied to the rotor core in a direction of the end surface of the rotor core to the end ring corresponding to the rotor core, so that relative movement between the rotor core and the formed end ring is reduced in the process of manufacturing the end ring corresponding to the other end surface. The first end ring corresponding to the first end face of the rotor core is manufactured through the additive, then a limiting force from the first end face to the first end ring is applied to the rotor core, the limiting force is continuously applied, meanwhile, the second end ring corresponding to the second end face of the rotor core is manufactured through the additive, and therefore relative movement between the rotor core and the first end ring in the process of manufacturing the second end ring through the additive is reduced.

Alternatively, in the additive manufacturing by the selective laser sintering method, in order to reduce the influence of gravity on the additive manufacturing, the first end ring and the second end ring may be manufactured separately. Specifically, the rotor core is rotated, so that the first end face of the rotor core is approximately parallel to the horizontal plane, and a first end ring is formed by additive manufacturing from the first end face outwards along a first direction; after the first end ring is formed, the rotor core is rotated again such that the second end face of the rotor core is substantially parallel to the horizontal plane, and a second end ring is formed from the second end face outwardly in the first direction by additive manufacturing. The horizontal plane may be a plane of relatively completely stationary water, and the horizontal plane may be perpendicular to a direction of gravity, so that the first end face and the second end face are respectively substantially parallel to the horizontal plane in a process of manufacturing the first end ring and the second end ring through additive manufacturing, so that the first end face can bear metal powder for forming the first end ring in a process of manufacturing the first end ring through additive manufacturing, and the second end face can bear metal powder for forming the second end ring in a process of manufacturing the second end ring through additive manufacturing, without additional bearing structures.

As shown in fig. 13, step S2 specifically includes:

step S211, spraying metal powder with preset thickness on the bearing base surface, and sintering the technical powder into a first cross-section layer with a corresponding shape through laser according to the structure of the motor rotating shaft.

Specifically, in the design process, according to the thickness of the section layer formed by sintering each time by a laser sintering method, the motor rotating shaft is divided into a plurality of continuous design section layers along the length direction of the motor rotating shaft, a first design section layer is determined according to the manufacturing sequence of each design section layer, and metal powder is sintered into a first section layer consistent with the shape of the first design section layer by laser. For example, if each cross-sectional layer of the motor shaft is sequentially manufactured from a first end of the motor rotor to a second end opposite to the first end in the first direction, the cross-sectional layer including the first end, or the cross-sectional layer closest to the first end, is determined as the first cross-sectional layer. It should be noted that, the design section layer is a virtual structure into which the model of the motor shaft is cut in the design process, and the virtual structure is a manufacturing target in the additive manufacturing process, not an actual structure.

Step S212, spraying metal powder on the first cross-section layer and sintering to sequentially form additional cross-section layers, so that the first cross-section layer and each additional cross-section layer are solidified to form the motor rotating shaft.

Optionally, each section layer of the motor shaft is sequentially manufactured from a first end of the motor rotor to a second end opposite to the first end along the first direction, and each adjacent section layer is sequentially sintered into a motor shaft with a shape consistent with that of the required motor shaft, so that the integrally formed motor shaft is obtained.

Optionally, after each sintering to form one cross-sectional layer, the cross-sectional layer is cleaned of excess metal powder, and after the excess powder is cleaned, the next cross-sectional layer is manufactured to prevent the excess metal powder from affecting the manufacture of the cross-sectional layer at a time.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. An electric motor rotor, at least part of which is produced by additive manufacturing, the electric motor rotor comprising:

a squirrel cage assembly and a motor rotating shaft;

wherein, the motor shaft includes:

the mouse cage comprises a mounting part, a mouse cage assembly and a connecting part, wherein the mounting part extends along a first direction, a cavity is formed in the mounting part, and the mouse cage assembly is sleeved on at least part of the mounting part;

The transmission part is arranged at the end part of the mounting part and extends along the first direction, and the cavity is arranged in the transmission part;

in a section perpendicular to the first direction, the outer edge dimension of the mounting part is larger than the outer edge dimension of the transmission part, and the ratio of the outer edge dimension of the mounting part to the outer edge dimension of the transmission part is larger than 1.5;

wherein, at least one of the cavity in the installation part and the cavity in the transmission part comprises a closed cavity, and the motor rotating shaft is integrally manufactured through additive manufacturing.

2. The motor rotor of claim 1, wherein the mounting portion comprises:

the mouse cage assembly is sleeved on the sleeved part, and the transmission part is arranged at the end part of the sleeved part;

the positioning part extends out of the circumferential outer surface of the sleeving part along the second direction and is abutted with one end of the squirrel cage assembly; wherein the second direction is substantially perpendicular to the first direction.

3. The motor rotor according to claim 2, wherein the distance by which the positioning portion protrudes from the circumferential outer surface of the fitted portion is greater than a preset threshold.

4. The motor rotor of claim 2, wherein a heat dissipation air duct is formed on an outer surface of the sleeve portion, and a length direction of the heat dissipation air duct is substantially parallel to the first direction.

5. The electric machine rotor of claim 1, wherein the squirrel cage assembly comprises:

the rotor core extends along a first direction and is sleeved on at least part of the mounting part;

the guide bars are arranged at intervals along the circumferential direction of the rotor core and penetrate through the rotor core;

the end rings are respectively arranged at two sides of the rotor core and fixedly connected with the guide bars.

6. The motor rotor of claim 5, wherein the end faces of the bars extending out of the rotor core are fixedly connected to the end rings, and the spacing between the end rings and the end faces of the rotor core is less than a preset value.

7. The electric machine rotor of claim 6, wherein the predetermined value is 5 millimeters.

8. The motor rotor of claim 5, wherein both end rings have mounting slots for receiving portions of the bars that connect with the end rings.

9. A method of manufacturing a motor rotor, the motor rotor comprising: an end ring;

a motor shaft according to any one of claims 1 to 8;

the manufacturing method comprises the following steps: and obtaining the end ring and the motor rotating shaft through additive manufacturing.